Vacuum-tube circuit



Aug. 6, 1929.

G. W. CARPENTER VA CUUM TUBE CIRCUIT Filed Oct. 27, 1923 2 Sheets-Sheet 1929- G. w. CARPENTER 1,723,013

VACUUM TUBE CIRCUIT Filed Oct. 27, 1923 2 Sheets-Sheet 2 Inventor:

Glenn \Mcarpenter;

y @wni His Attorney.

' condenser C Patented Au 6,1929.

UNITED STA GLENN W. CARPENTER, OF SCHENECTADY NEW YORK ASSIGNOR 'I'O GENERAL ELEG- ORATION OF NEW YORK.

VACUUM-TUBE 'cmcum' Application filed October 27, 1923.

My invention relates in particular to the use of vacuum tubes in receiver and transmitter circuits, and the object of the invention is to simplify the apparatus used in such circuits, for the detection and amplification of received signals, for the amplification of transmitted signals, and for the modulation of currents in signal transmission.

The principle involved in this invention may be used in circuits for radio telegraphy, radio telephony, or wire telegraphy and telephony,

A fundimental feature of the invention is the enclosure within a single vacuum chamber of the elements of a plurality of vacuum tube devices such as are familiar in the art of radio communication, the several sets of elements being capable of functioning normally and independently ofeac'hother. Another fundamental feature of the invention is the use of but a single filament with a plurality of such sets of elements.

Other advantages and uses of the inventlon will appear in the description and drawings, which follow.

In the accompanying drawings:

Fig. 1 is a circuit diagram showing the use of the improved tube as a radio frequency detector and a one-step amplifier;

Figure 2 is a circuit diagram showing the use of the improved tube as a two-step ampli- Figure 3 is a circuit diagram showing the use of the improved tube as a detector and multistage amplifier;

Figure 4 is a circuit diagram showing the use of the improved tube as a transmitter in radio telephony or telegraphy; and

Figure 5 is a circuit diagram showing the use of the improved tube as a multistage amplifier, using a combination of resistance and capacity coupling between successive stages.

Referring to Figure 1, one plate P one grid G and the detector in the usual way, with the blocking or, as indicated in dotted lines, without it. The other half of the tube, comprising plate P grid G and filament F, is used as an amplifier. The leads marked 1 and 2 are the input terminals and are connected to the voltage supply to be detected and amplified in the usual manner familiar in the ar filament F are used as a Serial No. 671,254.

The first plate P is connected through the primary p of a transformer vT to the so-called .Bf battery or plate battery B. A large capaclty C is connected in shunt to the Bbattery to form a low impedance path for the alternating current. A capacity connected in shunt to the primary p for tuning to any desired frequency.

he secondary 8 of transformer T is connected to the second grid G and to the negatlve side of the filament F which is supplied with current from the A battery or filament heating battery A. Proper polarity of the transformer connections must be carefully observed or else troublesome howling is likely to occur. The plus and minus signs on the drawings refer only to the alternating components of the currents at a particular The operation follows: A varying potential is impressed on the terminals 1 and 2. If this varying potentlal is in the form of a damped high frequency oscillation, the elements P G and F function as a detector in the usual way known in .the art. The audio frequency current exist mg in the plate circuit P due to this detector action may then be transferred to the input circuit of the other half of the tube by any unstable coupling means known in this art, shown in Figure 1. Two transformers T The second grid-and-plate set amplifies the audio frequency signal as though it were in an entirely separate tube. devices, such as telephones or a recorder, are connected in the plate circuit P The circuit for a two-stage amplifier, shown 1n shown in Fig. 1. W0 transformers T and T are used, and both sides of the tube are used as amplifiers. Capacities O and O like capacity C in Fig. 1, are used for tuning the circuit to take the desired frequency. Terminals 3 and 4 are the input terminals and may be connected in circuit with the detector (not shown) whose output is to be amplified. Here again the polarities-marked on the transformers in Figure 2 are correct only when speaking of ponents of the currents at a particular instant.

The same principle as illustrated in Figum 1 may be applied to a tube containing several of this arrangement is as' TES PATENT o FFIoE., -i7

The translating Figure 2, is almost identical with that.

the alternating comgrid-and-plate sets with a common filament arranged to form a detector and a multistage amplifier as shown in Figure 3. Each of the above grid-and-platesets may cons1st of a plurality of grids and a plurahty of plates, all associated with a common filament, and each group of grid-and-plate sets acting as a separate vacuum tube. The action is the same as in Figure 1. The output circuit of the second grid-and-plate set is coupled to the input circuit of a third grid-and-plate set through one of the coupling devices mentioned above. The translating device is connected in the output circuit of the third gridand-plate set as shown in Figure 3. This cascade arrangement may be used for any number of steps of amplification.

Figure 4 illustrates a method of using the princi le involved in my invention, in the ampli cation of modulations in undamped signal transmission as in radio telephony, or in the amplification of radio frequency currents in undamped radio telegraph transmission. The elements P G1 and F are connected to form an oscillating circuit in the usual way. This may be accomplished by connecting the primary p and the secondary s of a transformer T in the plate and grid circuits respectively of the first grid-and-plate set. The oscillating energy in the plate circuit is then repeated to the grid G of the second grid-and-plate set by means of a second trans former T The elements P G2 and F serve as an amplifier of the energy supplied by the first grid-and-plate set. The antenna and ground may be connected to the coil Q, in

circuit with the plate P The key K may be used to operate the device as an undamped wave transmitter. To use the device as a transmitter of the human voice, theoperator speaks into the microphone M. The undamped oscillations produced by the first grid-and-plate set are modulated by the voice currents in the secondary of the transformer T The modulated energy is then amplified by the second grid-and-plate set and communicated to the antenna by the coil Q.

Figure 5 illustrates a method of using the improved tube as a cascade amplifier, the successive steps being coupled by a combination of resistance and capacity. This arrangement is very desirable for radio frequency amplification. The last grid-and-plate set acts as a detector in the usual way, while the preceding ones act as radio frequency amplifiers.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. The combination in a system for the re ception of electricimpulses, of a vacuum tube enclosing a single filament and a plurality of grid-and-plate sets each of which comprises an individual grid and plate associated therewith all of which are so located with respect to the filament that electrons may be received from the entire length thereof, circuits connecting said filament and grid-and-plate sets in cascade and a common source of energy for supplying all of the current to all of the plates.

2. The combination in a system for the communication of electric impulses, of a vacuum tube enclosing a filament and a plurality of grid-and-plate sets associated therewith all of which are so located with respect to the filament that electrons may be received from the entire length thereofi, an input circuit connected toa detector group of said grid-and-plate sets, cascade amplifier circuits connected between said detector group and the remaining grid-and-plate sets and a common source of energy for supplying all of the current to all of the plates.

3. The combination in a system for the communication of electric impulses, of a vacuum tube enclosing a filament and a plurality of grid-and-plate sets each of which comprises an individual grid and plate associated therewith all of which are so located with respect to the filament that electrons may be received from the entire length thereof, coupling means, and circuits connecting said filament and grid-and-plate sets in cascade by said coupling means and a common source of energy for supplying all of the current to all of the plates.

4:. The combination in a system for the communication of electric impulses, of a vacuum tube enclosing a filament and a plurality of grid-and-plate sets each of which comprises an individual grid and plate associated therewith all of which are so located with respect to the filament that electrons may .be received from the entire length thereof, induction coupling means and circuits connecting said filament and grid-and-plate sets in cascade by said coupling means.

5. The combination in a system for the communication of electric impulses, of a vacuum tube enclosing a filament and a plurality of grid-and-plate sets associzied therewith, circuits connecting said filament and one group of grid-and-plate sets arranged to generate and modulate an alternating current, and cascade amplifier circuits connected between said first group and the remaining grid-and-plate sets.

6. An amplifying valve having a filament and two grid-and-plate pairs symmetrically grouped respectively on each side of the filament to form a six terminal valve, the two grid-and-plate pairs being arranged in cascade connection 'by inductive coupling means.

.7. In a telephone receiving circuit, an amplifying valve having a filament and two grid-and-plate pairs symmetrically grouped respectively on each side of the filament to form a six terminal valve, the grid of one to the circuit from which the signals are reof said transformer and a filament terminal, ceived, the plate of the same pair being conand a fourth circuit, including the plate of the nected to a filament terminal, a direct cursecond pair, said direct current source, a lo rent source in circuit therewith, a transtelephone and a terminal of the filament. 5 former having its primary coil in said plate- In witness whereof I have hereunto set my filament connection, a third circuit, includ-' hand this 26th day of October, 1923. ing the grid of the other pair, the secondary GLENN W. CARPENTER.

CERTIFICATE OF CORRECTION.

Granted August 6, 1929. to Patent No. 1,723,013.

GLENN .W. CARPENTER.

I I V I l I f It is hereby certified that error appears n the prlntled spicligzzllsin :trikc above numbered patent requiring correction as ffollows:T susage? ,and insegt instead Two trans ormers words "shown 1n Figure 1. 8 Patent iiir ifistance, an inductive transformer T and that the rid zfiftzlrm to the should be read with this correction therein that the same y tent Office. record of the case in the Pa Signed and sealed this 10th day of September, A. D. 1929 M. J. Moore, Acting Commissioner of Patents. (Seal p 

